Method and apparatus for raising and permanently supporting heavy structures



T." P. LENAHAN nA'rUs Fon RAIsI ,855 NG AND PERMANENT nucTunEs June 29,'1943. l

METHOD AND AFPA SUPPORTING HEAVY ST Filed Feb VINVENTQR THOMAS RLENA'HAN Patented June 29, 1943 Y METHOD AND APPARATUS FOR RAISING ANDPERMANENTLY SUPPORTING HEAVY STRUCTURES Thomas P. Lenahan, Duncan,Okla., assignory to Halliburton Oil Well Cementing Company,

Duncan, Okla.

Application February 9, 194,2, Serial No. 430,096

2 Claims. (Cl. (i1-51) This invention relates to method and apparatusfor raising and permanently supporting heavy structures such as dams,bridge piers, docks, foundations and the like, which have settled orshifted.

Load sustaining structures of the type mentioned are sometimes locatedin places where V:there is a layer of unstable earth, such as silt orsand, over the load bearing substratum or bed rock. As a result, thestructure sometimes sinks below its intended level, either wholly or atone Vside orcorner.

In accordance with the present invention, it is proposedto raise andpermanently support such structures by the employment of a hydraulicjack in which cement slurry is either used -as the actuating liquid orfollows the actuating liquid, the jack being so constructed that whenthe structure israised the desired) amount, valves may be closed and thecement allowed to harden,

leaving the jack permanently in place, it then -becoming a reinforcedconcrete column. I

If the structure is relatively small, or if only one corner of it hassunk` into the earth, it may be vpossible to bring it back into thedesired position by the use of only one jack. If a large structure-hasto be raised, however,` any number yof vjacks may be employed and thearrangement `for supplying the cement` slurry thereto may be such thatthe jacks exert their lifting force either one after the other orsimultaneously. I Accordingly, it is an object of the present inventionto provide a novel system for raisinga heavy structure such as a pierand for permanently holding it in place.

It is another object of the present invention to devise novel methods ofraising heavy structures and for holding them in place.

Other objects and advantages reside in certain novel features of themethod and the arrangement of parts, as will be apparent from theiollowing description taken in connection with the accompanying drawing,in which:

Figure 1 is a diagram showing a planview of a pier with a system ofjacks, valves, pumps, etc., for raising it in accordance with thepresent invention; and

Figure 2 is a partial cross-sectional view of a hydraulic jackconstructed in accordance with the principles of the invention.

Referring to the drawing in detail, and first to the arrangement ofFigure 1, it will be seen that a pier is there illustrated at II. Inorder to illustrate the invention, let it be assumed that the entirepier has sunk into the earth and that it; is desired to raise the sameuniformly at all points.

In accordance with the present invention, suitable lifting members IZare secured to the pier at spaced points. In the diagram ofV Figure 1,six such lifting members are illustrated. 'These may be sections ofI-beams or other structural steel members and are secured to the pier inany suitable manner.

Beneath each of the lifting membersv I2, `hydraulic jacks I3 aremounted, the jackspreferably extending down to bed rock. The hydraulicjacks I3 are each supplied with individual supply conduits `I4. Each ofthese conduits is provided with a .Valve 'I5 and is connected to thesupply conduits I6, to which liquid under pressure may be supplied froma pump I1.

` The pump I1 may supply Water or other liquid tothe conduits I6 toinitially fill the jacks I3. At the desired time, the water maybereplaced `by cement slurry. InFigure 1, thecement mixer may `all besuppliedwith liquid simultaneously or successively. Likewise, any groupof jacks may selectively be supplied with liquid. Thus, if -desired, thevalves I5 at the rightof the figure may remain closed, while those atthe left are opened and Yliquid suppliedto the left-hand jacks,` afterwhich those valves may be closed and the ones on the right-hand side ofthe figure opened to raise the right-hand side, so that first one sideof the pier 'and then the other is lifted, the pier thus being rockedback and forth as it is lifted.

An important feature of the invention resides in the construction andmounting of each ndividual hydraulic jack. To place the jack inposition, a hole is first drilled along side the pier where it isdesired to locate the jack, the hole going down to bed rock. Theequipment for drilling this hole may be such as is commonly used indrilling oil wells.

Such a hole is illustrated at 2l in Figure 2. After the hole iscompleted, casing 22 is lowered therein and secured in place by placingcement 23 in the annular space between it and the wall of the hole 2|.The manner of carrying on this operation may be the same as thatemployed in cementing surface casing in oil wells.

The casing 22 may extend above the surface of the ground as illustrated,and is provided with a discharge conduit 24 equipped with a Valve 25.

Lowered into the .casing 22 is a jack pipe 26. Preferably this pipeshould extend to the bottom or nearly to the bottom of the hole 2|. Itis some longer than the casing 22 and extends up through structureproviding a suitable stuing box, as illustrated at 2l. An ordinaryBradenhead such as is used in the oil elds may serve as the stuflng box.

The upper end of the jack pipe 26 is provided with a cap 28 positionedjust beneath the lifting members I2 secured to the pier II. In thearrangement illustrated, the conduit I4 equipped with the valve Ireferred to above, is connected into the jack pipe 26.

It will be seen that with the structure illustrated, liquid may besupplied from the pump I'I to `the interior of the jack pipe 26, theliquid flowing in the direction of the arrows of Figure 2, assuming thevalves I5 and 25 are open. If desired, the lower end of the jack pipe 26may be provided with suitable discharge ports 29 to facilitate thiscirculation. (If desired, the circulation might be in the oppositedirection, the pump II then being connected to pipe 24.)

As illustrated, if at any time the valve 25 is partially or whollyclosed, pressure Will build up within the jack and cause the jack pipe26 to exert a lifting force upon the member I2.

Where conditions are ideal, no liquid will be placed in thejack prior tothe time that cement slurry is placed therein. In such a case, thevalves I5 and 25 will both Vbe opened, slurry pumped into the yjack andcirculated in the direction of the arrows, until a return is had throughthe conduit 24. The valve 25 will then be closed, and the supply ofcement-slurry to the jack continued until the'member I2 has been raisedthe desired amount, at which time the pumping will be discontinued, thevalve I5 closed and `the cement allowed to harden.

At other/times it may be necessary or desirable to use water or otherliquid for 'exerting the necessary pressure to lift the structure,

n this liquid to be followed by cement slurry with the valves I5 and 25carefully controlled, so that 'the desired position of the jack pipe 26is maintained.

In any event, cement will ultimately be left not only in the jack pipe26, but also in the annular space between it and the casing 22.

After the cement has hardened it, will be seen that a very rigid columnis provided, consisting of the outer body of cement 23 interlocking thecasing 22 with the earth, an intermediate body of cement between thecasing 22 and the jack pipe 26 and an inner body of cement left withinthe jack -pipe 26.

Of course, after the cement has hardened, the valves I5 and 25 and theconnecting pipes I4 and 24 may be removed from the column.

If the pier or other structure is raised by rocking motion, as mentionedabove, the cement in one set of jacks may be allowed to harden beforeslurry is supplied to the other set, the apparatus being capable of usein several different ways.

Also, it is, of course, possible to force cement or other supportingmaterial under the pier or other structure during or after theyapplication of the method and apparatus of this invention.

While only one embodiment of the invention has been shown and describedherein, it is obvious that various changes may be made in the method ofapplication or in the structure, without departing from the-spirit ofthe invention or the scope of the annexed claims.

I claim:

1. The method of raising and permanently supporting a structure whichconsists in drilling a plurality of holes in the earth, placing a casingin each hole, cementing the casings in place, placing jack pipes in thecasings through stufling boxes, lling the jack pipes and the casingswith liquid, exerting hydraulic pressure on the liquid to raise the jackpipes replacing the liquid in the jack pipes and casing with cementslurry while maintaining the hydraulic pressure therein, and holding thepressure until the cement hardens, the hydraulic pressure being exertedon the liquid alternately, to rock tl'ie structure slightly in raisingthe same.

v 2. The method of raising and permanently supporting a structure whichconsists in drilling a hole in the earth, placing a casing therein,cementing the casing in place, placing a jack pipe in the casing througha stung box, filling the jack pipe and the casing with a liquid,exerting hydraulic pressure on the liquid to raise the jack pipe,replacing the liquid in the jack pipe and casing by cement slurry whilemaintaining the hydraulic pressure therein and while maintaining thejack pipe in its raised position and holding the pressure until thecement hardens. l

THOMAS P. LENAHAN.

